CAMEL-14180: Fix Checkstyle issues
Seems that previous versions of Checkstyle had few issues with checking
import sort/grouping. So I've run impsort Maven plugin:
mvn net.revelc.code:impsort-maven-plugin:sort -Dimpsort.groups=java,javax,org.w3c,org.xml,junit -Dimpsort.removeUnused=true -Dimpsort.staticAfter=true
To sort all the imports according to the Checkstyle rule.
Few remaining issues around indentation and unnecessary parentheses I
fixed manually.